Microsoft Power BI Data Analyst PL-300 Practice Test 9
Question 80
An orders feed has null quantity values that mean missing source information, while zero quantities represent legitimate canceled items. A pilot instead implemented the following proposed change: Replace all null quantities with zero without a business rule. The business requirement was not met. Which technical limitation MOST DIRECTLY explains the result?
- Text conversion does not determine the business meaning of missing values
- Null denotes absent data whereas zero is a valid quantity and should not be silently invented
- Zero is a legitimate business value in the specified data
- Automatic zero imputation would conflate missing data with a genuine zero
Explanation
Correct Answer
D:Automatic zero imputation would conflate missing data with a genuine zero This specifically addresses the deployed or proposed alternative: Replace all null quantities with zero without a business rule.
Incorrect Answers
A:Text conversion does not determine the business meaning of missing values That limitation describes Convert the quantity column to Text and compare string literals, not the specified approach.
B:Null denotes absent data whereas zero is a valid quantity and should not be silently invented This supports the recommended design but does not diagnose why the specified alternative fails.
C:Zero is a legitimate business value in the specified data That limitation applies to a different alternative (Delete every row containing a quantity of zero), not the one here.
Question 81
A sales table must enrich each invoice with a customer segment from a Customer lookup using CustomerID. Which Power BI or Power Query action BEST meets the stated requirement?
- Duplicate Customer and hide the source table
- Append Customer rows below Sales rows
- Unpivot all Sales measure columns
- Merge Sales and Customer by CustomerID and expand the segment column
Explanation
Correct Answer
D:Merge performs key-based row matching to bring lookup attributes into a table This addresses the specific requirement: a sales table must enrich each invoice with a customer segment from a Customer lookup using CustomerID.
Incorrect Answers
A:A duplicate alone does not join attributes by CustomerID This alternative therefore fails an explicit scenario constraint.
B:Append stacks unlike entities and cannot match segments onto existing invoices This alternative therefore fails an explicit scenario constraint.
C:Unpivot changes measure-column layout without looking up customer attributes This alternative therefore fails an explicit scenario constraint.
Question 82
A published Import model loads from a corporate SQL database but works in Desktop only; the scheduled service refresh reports invalid credentials. Which Power BI or Power Query action BEST meets the stated requirement?
- Change the report title and republish the visual pages
- Add a bookmark to refresh the report page on click
- Add a DAX calculated column that contains the login name
- Update the service semantic model's data source credentials for the correct connection
Explanation
Correct Answer
D:Desktop credentials are not automatically sufficient for refresh executed by the Power BI service This addresses the specific requirement: a published Import model loads from a corporate SQL database but works in Desktop only; the scheduled service refresh reports invalid credentials.
Incorrect Answers
A:A report title has no effect on semantic model source authentication This alternative therefore fails an explicit scenario constraint.
B:Bookmarks do not supply the missing server credentials This alternative therefore fails an explicit scenario constraint.
C:A DAX expression cannot authenticate service refresh to the database This alternative therefore fails an explicit scenario constraint.
Question 83
Two sales tables share a common Product dimension but each fact table repeats ProductID for transactions. Which Power BI or Power Query action BEST meets the stated requirement?
- Force ProductID to be unique in each sales fact
- Flatten all historical facts into the Product dimension
- Relate the two sales fact tables directly on ProductID
- Create a unique Product dimension with one-to-many relationships to both fact tables
Explanation
Correct Answer
D:Star-schema dimension keys describe products once while facts preserve repeated transactional foreign keys This addresses the specific requirement: two sales tables share a common Product dimension but each fact table repeats ProductID for transactions.
Incorrect Answers
A:Fact transactions legitimately repeat ProductID and cannot be collapsed to one row per product This alternative therefore fails an explicit scenario constraint.
B:Dimensions should describe business entities rather than store transaction-grain measures This alternative therefore fails an explicit scenario constraint.
C:A fact-to-fact relationship can multiply matches and introduce ambiguity This alternative therefore fails an explicit scenario constraint.
Question 84
A large SQL source supports folding and the analyst needs to reduce rows to one year before further shaping. Which Power BI or Power Query action BEST meets the stated requirement?
- Add a custom per-row Python transformation before the source date filter
- Disable all query folding checks and export every row
- Push the date-filter step early while query folding is preserved
- Buffer the entire source table before filtering
Explanation
Correct Answer
C:Foldable filtering lets the source restrict rows before transfer and local transformation This addresses the specific requirement: a large SQL source supports folding and the analyst needs to reduce rows to one year before further shaping.
Incorrect Answers
A:An unsupported local transform can break folding before the selective predicate This alternative therefore fails an explicit scenario constraint.
B:Disabling folding awareness does not optimize the requested early reduction This alternative therefore fails an explicit scenario constraint.
D:Buffering early can prevent folding and read more data than needed This alternative therefore fails an explicit scenario constraint.
Question 85
An orders feed has null quantity values that mean missing source information, while zero quantities represent legitimate canceled items. A design reviewer proposes this alternative: Delete every row containing a quantity of zero. Which objection BEST explains why it would not satisfy the stated requirement?
- Null denotes absent data whereas zero is a valid quantity and should not be silently invented
- Zero is a legitimate business value in the specified data
- Text conversion does not determine the business meaning of missing values
- Automatic zero imputation would conflate missing data with a genuine zero
Explanation
Correct Answer
B:Zero is a legitimate business value in the specified data This specifically addresses the deployed or proposed alternative: Delete every row containing a quantity of zero.
Incorrect Answers
A:Null denotes absent data whereas zero is a valid quantity and should not be silently invented This supports the recommended design but does not diagnose why the specified alternative fails.
C:Text conversion does not determine the business meaning of missing values That limitation describes Convert the quantity column to Text and compare string literals, not the specified approach.
D:Automatic zero imputation would conflate missing data with a genuine zero That limitation applies to a different alternative (Replace all null quantities with zero without a business rule), not the one here.
Question 86
A Power Query project combines confidential HR pay records with a public internet currency table and must prevent unintended private values from influencing queries sent to public sources. A design reviewer proposes this alternative: Disable privacy checks globally on all reports. Which objection BEST explains why it would not satisfy the stated requirement?
- A DAX table is not a substitute for configuring Power Query source privacy before combining data
- Declaring sensitive rows public weakens the intended privacy isolation
- Privacy isolation controls how Power Query combines data from sources with different sensitivity boundaries
- Ignoring privacy levels removes the source-combination protection rather than resolving it safely
Explanation
Correct Answer
D:Ignoring privacy levels removes the source-combination protection rather than resolving it safely This specifically addresses the deployed or proposed alternative: Disable privacy checks globally on all reports.
Incorrect Answers
A:A DAX table is not a substitute for configuring Power Query source privacy before combining data That limitation describes Make the public currency URL a calculated DAX table in the final model, not the specified approach.
B:Declaring sensitive rows public weakens the intended privacy isolation That limitation applies to a different alternative (Mark the confidential HR source as Public to remove the firewall warning), not the one here.
C:Privacy isolation controls how Power Query combines data from sources with different sensitivity boundaries This supports the recommended design but does not diagnose why the specified alternative fails.
Question 87
A CSV Date column contains dates in day-month-year order and Power Query mistakenly interprets several dates as month-day-year under a US locale. A design reviewer proposes this alternative: Sort the text column descending and keep it as Text. Which objection BEST explains why it would not satisfy the stated requirement?
- Locale-aware parsing resolves the date order rather than accepting ambiguous incorrect dates
- Formatting a measure does not repair incorrectly parsed Power Query dates
- Text sorting cannot establish a valid chronological date type
- Changing separators does not reliably correct day and month interpretation
Explanation
Correct Answer
C:Text sorting cannot establish a valid chronological date type This specifically addresses the deployed or proposed alternative: Sort the text column descending and keep it as Text.
Incorrect Answers
A:Locale-aware parsing resolves the date order rather than accepting ambiguous incorrect dates This supports the recommended design but does not diagnose why the specified alternative fails.
B:Formatting a measure does not repair incorrectly parsed Power Query dates That limitation describes Create a DAX FORMAT measure and leave the source dates as strings, not the specified approach.
D:Changing separators does not reliably correct day and month interpretation That limitation applies to a different alternative (Replace every slash with a hyphen while retaining the US locale), not the one here.
Question 88
A shipment table has millions of line-level rows and a downstream summary needs total weight by depot and month only. A pilot instead implemented the following proposed change: Remove duplicates on depot alone. The business requirement was not met. Which technical limitation MOST DIRECTLY explains the result?
- Appending doubles the underlying shipments and the totals
- Grouping produces a smaller summary grain with specified total weight per group
- Removing duplicates drops legitimate shipments instead of summing them
- Transposition changes orientation without computing group totals
Explanation
Correct Answer
C:Removing duplicates drops legitimate shipments instead of summing them This specifically addresses the deployed or proposed alternative: Remove duplicates on depot alone.
Incorrect Answers
A:Appending doubles the underlying shipments and the totals That limitation describes Append the table to itself, not the specified approach.
B:Grouping produces a smaller summary grain with specified total weight per group This supports the recommended design but does not diagnose why the specified alternative fails.
D:Transposition changes orientation without computing group totals That limitation applies to a different alternative (Transpose the entire source table), not the one here.
Question 89
A temperature sensor file contains several Error cells in a measurement column but the analyst must retain other valid measurements from those rows. After the correct solution is implemented, which result provides the MOST DIRECT evidence that the requirement actually works?
- The first thousand preview rows look correct, but the known invalid or missing records have not been examined
- The column type icon appears correct, but a source-to-result reconciliation has not been performed
- The query loads successfully, but distinct values and data-quality exceptions were not checked
- Only the affected measurement cells receive the approved fallback while unrelated record fields remain intact
Explanation
Correct Answer
D:Only the affected measurement cells receive the approved fallback while unrelated record fields remain intact This exercises the requested business outcome and the necessary positive or negative boundary.
Incorrect Answers
A:A short preview may miss the very error, locale or null condition that the cleaning rule must handle.
B:The declared type alone cannot establish that actual identifiers, dates or values survived transformation.
C:Successful load does not prove the requested missing-value or identity semantics were preserved.
Question 90
A Power Query project combines confidential HR pay records with a public internet currency table and must prevent unintended private values from influencing queries sent to public sources. After the correct solution is implemented, which result provides the MOST DIRECT evidence that the requirement actually works?
- One report visual renders without an error while its data recency and intended source identity remain unchecked
- Power BI Desktop shows a successful source preview, but no service connection or target refresh has been exercised
- Privacy settings reflect confidential and public classifications and the merged query loads without leaking HR values into public-source requests
- The connection settings have been saved, but no comparison to the required source data has been made
Explanation
Correct Answer
C:Privacy settings reflect confidential and public classifications and the merged query loads without leaking HR values into public-source requests This exercises the requested business outcome and the necessary positive or negative boundary.
Incorrect Answers
A:An error-free visual might be cached or backed by the wrong source; it does not test the specified freshness or connectivity boundary.
B:A Desktop preview establishes local connectivity only; it does not verify the published data-access behavior requested here.
D:Saved configuration is not evidence that the selected storage/credential behavior returns the intended records.